The present invention belongs to food production in which food materials in a fluid state (fluid food materials) which solidify when cooled are cooled and shaped successively at a certain thickness, and relates to a method and a device of producing two-or-more-layer laminated food from two or more sorts of food materials with different properties, and to laminated cheese food thus produced.
Laminated food produced by food materials with different properties being piled was often manufactured in accordance with a batch method making use of molds and the like conventionally. According to this method, since food materials in a fluid state can be cooled and solidified while being left at rest, there are few technical limitations to production. However, the method had a problem of the difficulty of improving productivity on account of the complicated batching, production rate, the setting area of a device, the number of workers, and the like.
In order to produce laminated food successively, it is necessary to cool and solidify food materials in a fluid state and at the same time to shape the food materials and bond the layers. Accordingly, there arise a number of factors to be considered such as fluid properties, heat transfer properties of food materials, and integrity between food materials. In particular, in the case of laminated food in which a plurality of food materials are piled in a plate form, it is impossible in principle to stir or mix the food materials after the layers are formed. Therefore heat transfer decreases inevitably and cooling efficiency lowers accordingly. As a result, the decrease in production efficiency becomes a problem.
On account of the above-mentioned problems, the successive production of laminated food has hardly been done.
In accordance with a method of successively manufacturing platy products made of a single food material, thin-plate-like cheeses or rice cakes are produced, and in accordance with a semibatch method of successively manufacturing laminated food, jellies and chocolates are produced.
Jpn. Pat. Appln. KOKAI Publication No. Hei 3-201952 (1991) discloses a means of successively producing multilayer jelly in a semibatch method. According to the production method, however, a food material in a fluid state is poured into a mold and solidified, and then another food material in a fluid state is poured and solidified again. Therefore this method is practically identical to the conventional batch methods making use of a mold, and thus has the afore-mentioned problems.
Jpn. Pat. Appln. KOKAI Publication No. Hei 5-336870 (1993) discloses a means of successively producing multilayer pies. According to the production method, however, a semisolid food material such as pie dough is discharged on a conveyer and piled. This food material is not in a fluid state, and is not the object of this patent application.
As described above, in order to increase the number of layers of a plurality of food materials in a fluid state successively, it is necessary to shape the food materials and bond the layers while cooling and solidifying the food materials. Accordingly, there arise a number of factors to be considered such as the way of shaping, cooling and bonding food materials, and production efficiency.
If food materials discharged in a thin plate form on a cooling and carrying side of a cooling and carrying devices are bonded to other food materials to form laminated food by means of a simisolid outer surface not yet completely cooled and solidified of the food materials, the adhesive power of the layers is greatly influenced by the surface conditions and temperature of the other food materials, the temperature of the semisolid side of the thin-plate-like semisolid food materials.
The present invention was created to solve the above-mentioned problems, and the object of the present invention is to shape, cool and solidify, and unite two or more sorts of fluid food materials which are melted by the application of heat, or are fluid at room temperature but solidify when cooled with efficiency and accuracy in order to form two-or-more-layer laminated food.
As an example of laminated food manufactured in accordance with the above-mentioned production method, there is laminated cheese food.
At present, cheese products, mainly process cheese, are not provided such that each product shaped in a plate form is wrapped separately but are provided such that from several to dozens of products are piled directly and then wrapped together. The advantage of this form of product lies in the convenience of the product being cut in advance, and in that there are not many packaging media to be thrown away after use. Since consumers are becoming more and more conscious of the need to protect the environment recently, it is expected that this type of products will be favored more and more in the future.
However, if cheeses are piled and preserved for a long time, the adjoining cheeses generally adhere to each other on the contacting surface thereof. Accordingly it becomes necessary to devise a means to prevent the adhesion and to enable each layer of the piled cheeses to come away from one another smoothly.
A variety of ways of preventing the adjoining cheeses from adhering to one another after being piled have been devised mainly with respect to process cheese.
There have been proposed methods such as a preparation method in which cheese material which contains mature cheese and inmature cheese with low maturity (matured less than a month) is used (Jpn. Pat. Appln. KOKAI Publication No. Sho 58-47432 (1983)), a preparation method in which cheese material containing 50 wt % or more of natural cheese the maturing of which is retarded or natural cheese matured less than a month is used (Jpn. Pat. Appln. KOKAI Publication No. Hei 4-179442 (1992)), a preparation method in which material cheese containing 30 wt % or more of immature natural cheese and 0.05 to 1 wt % of viscous polysaccharide is used (Jpn. Pat. Appln. KOKAI Publication No. Hei 5-146250 (1993)), a preparation method in which molten salt comprising hypophosphate, tripolyphosphate, polyphosphate, or the mixture thereof is added to cheese material (Jpn. Pat. Appln. KOKAI Publication No. Hei 8-196209 (1996)), a method in which 0.15 wt % or more of whey protein is contained in entire protein (Jpn. Pat. Appln. KOKAI Publication No. Hei 8.256686 (1996)).
According to the method disclosed in Jpn. Pat. Appln. KOKAI Publication No. Sho 58-47432 (1983) and Jpn. Pat. Appln. KOKAI Publication No. Hei 4-179442 (1992) in which material cheese with low maturity is used, however, it is difficult to realize a rich savor peculiar to mature cheese, and the product tends to be hard and elastic when tasted, as is the case with immature cheese.
And according to the method disclosed in Jpn. Pat. Appln. KOKAI Publication No. Hei 8-196209 (1996) and Jpn. Pat. Appln. KOKAI Publication No. Hei 8.256686 (1996), the target cheese is relatively hard cheese the main component of which is Gouda cheese and Cheddar cheese. This method does not provide a technique for giving releasability to extremely soft cheese such as cream cheese, or soft cheese with high water and fat.
Many methods according to the prior art have no descriptions about pH of cheese. Judging from the examples and the like, however, it is supposed that the pH ranges from about 5.5 to 6.5, and those methods do not provide a technique for giving releasability to sour cheese with high acidity and low pH (pH 5 or less).
In short, according to the conventional methods, it was impossible to shape extremely soft cheese such as cream cheese, soft cheese with high water and fat, and sour cheese with low pH, into a plate form, and thereby to form the multilayer laminated cheese.
Thus another object of the present invention is, according to the afore-mentioned production method, to provide laminated cheese food having an excellent savor and taste such that each layer of cheese may come away from one another smoothly even if a plurality of cheeses shaped into a plate form are piled.